Abstract: This invention relates to a device for welding cylindrical elements headwise to one another, whereby the welding is achieved by subjecting the cylindrical parts during the welding operation to a radial pressure near the welding area, which radial pressure may be directed inwardly or outwardly, whereas the device employed comprises an elastic ring to be arranged around the parts to be welded, said ring being accommodated in a sleeve in which a conduit for the supply of pressurized medium to the space between the ring and the sleeve is arranged.

Abstract: Holder for a welding head for carrying out welds on the innerside of a substantially closed body, said holder being in the form of an elongated member, the end portion of which is provided with a holding member for the welding head adapted to pivot from an axial position to a radial position, and wherein means are provided for controlling said holding member.

Abstract: Lattice for the giving of sideways support to fissile rods as used in a nuclear reactor, or other rods or pipes, likewise subjected to heat exchanging conditions, as for example in a heat exchanger. The lattice is composed of elongated metal strips, connected at intervals by transversely poised brackets, consisting of narrow strips, of which the connecting edges are bended into lips, set at an angle, to be fixed at the elongated strips.

Abstract: Lattice, especially for supporting sideways a bunch of nuclear fuel rods, constructed according to the egg-crate principle, in which fixing lips of alternating different lengths are stamped and bend out of the bands and cross-bands from which the lattice is composed, and are spotwelded to these bands.

Abstract: Fissile element that can be easily assembled and also afterwards taken apart. This is facilitated by the use of tilting bolts and snap connections. The assembling may be done by freezing in of the bunch of fissile rods in demineralized water.